Ignition-switch.



I. F. CAVANAGH.

IGNITION SWITCH.

APPLICATION FILED ocT. 2|. 1916.

1 ,232,458. Patented July 3, 1917.

2 SHEETS-SHEET I.

J. F. CAVANAGH.

IGNITION SWITCH.

APPLICATION FILED ocT.21,1916.

1 ,232,458. Patented July 3, 1917.

2 SHEETS-SHEET 2.

UNITED sTATEs PATENT oEEioE.

JOI-IN F. CAVANAGI-I, OF MERIDEN, CONNECTICUT, ASSIGNOR TO CONNECTICUT TELE- PHONE & ELECTRIC COMPANY, OF MERIDEN, CONNECTICUT, A CORPORATION OF CONNECTICUT.

. IGNITION-SWITCH.

engine contacts in closed-circuit condition4 and to thereby protect the coil and 'other mechanism from injury.

A special object is to provide means for holding the circuit in closed condition, which will securely hold the parts in this relation without being affected by current fluctuations in the normal operation and which will operate quickly to break the circuit under abnormal conditions.

Another object isV to combine with the automatic current interrupting mechanism manually operable means for controlling -of changes and modification the circuit independent of the automatic control. l

Further objects are to accomplish the foregoing in a simple compact construction, preferably-.in the nature of a single unit whicl can be easily wired and mounted in place and which will be relatively inexpensive to produce.

Other features of the irmitand details of construction will appear as the specilication proceeds.

In the accompanying drawings' I have illustrated my invention embodied in practical commercial formY but l would have it understood that the invention is susceptible without departure from the true spirit and scope of the invention.

In said drawings:

Figure 1, is an inside view of the switch unit withthe switch in open-circuit condition.`

Fig. 2, is a` longitudinal sectional View of the same with the push button forced in to hold the switch closed.

Fig. 3, is a cross sectional view. taken substantially on the plane ,of the line fil-8 of Fig. 2.

Fig. Zl, is a horizontalv sectional view taken substantially. on the plane of the line 4k of Fig. 1.

Fig. 5, 1s a fragmentary sectionalfview .Specification of Letters Patent.

F. CAvANAGH,

- Patented July 3, 1917.

Application filed. October 21, 1918. Serial No. 126,965.

taken substantially on the plane ofthe line 5 5 of Fig. 2 and illustrating the automatic releasing of the thermostatic holding member from the operating plunger.

, Fig. 6, is a more or less diagrammatic view of the switch and circuits controlled thereby.

In the structure disclosed the ignition switch is made up of two spring contacts 7 and 8 which are forced into electrical engagement with each other by means of an operating member in the form of a plunger 9 which is guided for movement toward and away from the switch contacts in a bushing 10. These parts are supported in operative relation in the present disclosure by mounting them in a metallic casing 11, the switch contacts being disposed in the bottom portion of this casing and supported on suitable insulators 12 and the bushing being .secured in the top of the casingas by seating it in an opening 13, said bushinghaving a shoulderportion 14.-l engaging the under side of the top and outwardly struck lugs 15 engaging the upper side of the-top wherelby said bushing is rigidly supported in' place. rThe plunger is preferably insulated from the switch as by providing it with an insulatingbutton 16 on its lower end where it engages with the upper contact.

rThe switch is normally held in the closed circuit condition illustrated in Figs. 2,' 3 and 6 by means of a thermostatic holding device which here takes the form of a thermostatic the locking shoulder on the plunger may consist of an annular head or enlargement on the lower end of the plunger, which head is shown in the form of a truncated cone to provide the inclined face 20 for forcing the thermostat laterally to one side during .the downward circuit closing movement of the plunger.

The holding-actionexerted by the thermof stat whenthe plunger has been pushed in to the circuit closed position will be clear from Figs. 2 and wherein it will be apparl ent thatthetplunger is held inward by the inter-engagement of the locking shoulders on the thermostat and plunger against the shoulder thereon out of engagement with a thermostatic bar nition circuit the shoulder on the plunger, the plunger and permitting the switch contacts to separate. The means for thus heating the thermostat is shown as a heating coil 21 mounted on the thermostatic bar, connected with the bar at one end at 22 and providedvwith a terminal contact 23 at the opposite end.

The coil of the holding thermostat is nor" thus releasing Vmally out of circuit so that said member serves normallysolely as a means for holding the circuit closed and is unaffected by fluctuations in current strength or other conditions in the ignition system. When however the circuit is left closed for a period of time that might injure the apparatus the heating coil of the holding thermostat is placed in circuit, inthe present yillu-stration by a second thermostat consisting of 24 carrying a contact 25 for engagement with the heating coil contact23 and provided itself with a heating coil 26. The heating coil of this second thermostat is normally connected in so as to be iniuenced'by conditions therein and is shown` connected at one end at 27 to the thermostatic bar and at its opposite end at 28 to a terminal 29.

he coil 26 is shown placed in series with the ignitionl con-tacts by a bar 30 extending from the base of the thermostat bar'over the upper switch contact 7, the actual/eo tact being here made by the engage/@nent Vof the end of the bar 30 w/ith/th/ehead of the rivet 31 which holdsihe'contactf?4 in place. The baseofhecond thermostat is shown angle/dwith respect'to the body of thejbar the. casingffroiny that sidepon and secured by means'of suitable fastenings 32 oninsi'ilators3/atY the opposite side of which the switch/'contacts'are mounted. Also for the skeyo'f compactness the second thermostat.

disposed at the opposite" bar ispreferably side ofthe plungerf'r'om that side where the holding thermostat is located.

Fig. 6 illustrates a typical circuitarrange'-, nient wherein the current from a battery 3 4 is conducted toxa terminal connected withthe. lower switch 'contact as by means of' anv arm 36 'integral with said cogtaet and-I through said lower contact'to the upper conconnection 30 5to-the ermostat bar 24,'through the coil 26 von the ig- Thelpush button "the, closing of the' switch is 'providing .a Spring said bar to the terminal 29 and thence by a conductor 37 through the primary 38 of an induction coil and conductor 39 to the dis- The circuit closer thermostat does not op- .f

crate in the normal `running of the engine and only becomes suliiciently heated to close the circuit when the primary circuit closed or when some such dangerous condition exists, the coil of such thermostat being for this purpose as illustrated of 'relatively heavy and coarse wire so as to carry the normal load without undue heating and to heat up suliiciently to operate the thermostat only by reason of an abnormal flow of current such as occurs when the engine stops with the breaker contacts in engagement.

When this occurs the circuit closer moves over and closesthe circuit for the heating coil' of the holding thermostat through the contacts 25-23. The current flow is then through the switch contacts and the heating coil of the circuit closer as before, and from the bar 24 of this tacts 25423 to the heating coil 21 of the holding thermostat and from the bar 17 of this thermostat to the metallic casing which supports it and by way of aterminal 42 which is connected with the metallic casing, to ground. vUnder thesecircuit conditions the holdingthermostat becomes heated and the thermostat bar 17 is thereby caused to be moved laterally away from the plunger and to 'carry the holding lug 18 away from n/ the engine isstopped with thermostat through congagement with the locking shoulder/on the plunger permitting the vp1 er cerise "under pressure of Ming contact.7 which results in t e/brealn/g of the ignition circui The heating coil 21 ofthe holding quickly and for the same reason a greater number of turns may be employed in this coil than in the coil of the circuit closer thermostat. v

preferably" also made manually operable for opening the i vnitioii circuit, this being provided for in the present disclosure, by constructing theholding thermostat so plunger when the to open the-switch. w

Qlhis yielding mounting forthe holding -therniostat isprovided in pivotally '.'supporting the holding thermo; l1.215 holding' end'onv a supporting` stud 43 which to the'back of the me? .tallic casing by means of a nut 44 andwby 45 which engages the topf. f 130557 the illustration, by

"stat 'at the end4 farthest removed from they is ':suit'ably secured of the` casing, which is coiled aboutv the piyotplunger which serves for I' ica' 1tp/tlpferrnostat'is preferably made of relatively l' ,1i-ne" wire as indicated, so as -to heat up as. to yield and release the plunger is pulled outward l limit the downward movement of such thermostat. To provide a. irm pivotal mounting for the thermostat, the thermostat bar is shown doubled back upon itselfv in U-Shaped 'form as indicated at 48, Figs. 4 and 6, the

pivot stud passing through both arms of this yoke formation and the outer arm being 'y disposed relatively lclose to the free end of the circuit closer thermostat and supporting' the contact 23 for engagement thereby.

This construction provides for the thermostat holding the plunger in the circuitclosed position and at the same time enables the thermostat to yield when the plunger is manually operated for the purpose of breaking the ignition circuits. To insure a positive disengagement of the before described locking shoulders when the plunger is withdrawn to break the circuit I have provided means operable under such conditions to positively shift the thermostat out of holding engagement with the plunger, such means comprising a beveled face 49 at the lower'end of the guide or bushing 10 for the plunger (Fig. 5) which is er gaged by a similarly inclined face 50 on the holding lug 18 in the upward yielding movement of the thermostat and which lacts to wedge or force the thermostat bar laterally and thereby release the lug 18 on the b ar from the shoulder 19 on the plunger.

Means are preferably provided for rapidly cooling the holding thermostat after it is automatically operated so as to quickly place the same in condition for holding the plunger in circuit-closed condition, in case it is desired to start the engine again soon after the switch has been automatically released. This cooling means here takes the form of a laterally extending cooling lug 51 of good l thermal conductivity on the end of the holding thermostat which, in the expansion of the thermostat comes into engagement with the wall of the metallic casing 11 thereby enabling the thermostat to quickly rid itself f heat 'by the communication of said heat to the walls of the supporting casing..

i, The terminals 29 and 35 may be mounted on an insulating base 52 which, as indicated in Figs. 1, 2 and 3, forms-a closure to the otherwise open lower side or bottom of the casing, said base resting on the lugs 53 turned inward at'the edges of such open Side. This insulating terminal base may be secured in place by theI middle grounded lterminal' 42 which is shown in the form of a tubular eyelet 54 extending :through the insulating base and through a lug 55'eXtendp ing forwardly from theback of the casing.

The other two terminals may also be in the form of tubular eyelets passed through the insulating baseand internally screw threaded to receive the terminal screws shown.

I have used the term thermostat herein to designate a suitable thermo electric element or device and similarly the terms employed throughout have been used in a descriptive rather than in a limiting sense, eX- cept so far as may be required by the prior art.

lWhat. I claim' is:

1. In an ignition system, the combination with ignition circuit contacts, a. device for closing the circuit through said contacts, a thermostatic element for holding said device in the circuit-closed position, a thermostatic circuit controller included in the ignition circuit, and a heating circuit for the thermostatic holding member controlled by said thermostatic circuit controller.

2. In an ignition system, an ignition circuit contact, a spring arm supporting said contact, an operating plunger for said spring arm, a thermostatic holding member engaging said plunger to ,holdy the same against the tension of the spring contact arm, a-thermostatic circuit controller included Vin the ignition circuit and a heating circuit for the thermostatic holding member controlled by said thermostatic circuit controller.

3. In an ignition switch, switch contacts, a push button for engaging said switch contacts, a thermostatic member engaging said push button to hold the same in the circuitclosed position and adapted when heated to release it from such circuit-closed position, a thermostatic circuitacontroller and a heating circuit for the thermostatic holding member controlled by said thermostatic circuit controller.

4. In a switch of the 4character described, switch contacts, an operating plunger for forcing said contacts into engagement, a. thermostatic member engaging said operating plunger to hold the same in the circuitclosed position and movable under heat lconditions out of holding engagement with said plunger and meansA yieldingly supporting said thermostatic holding member for enabling the-same to yield and release the plunger when said plunger'is moved to the plunger, meansl yieldingly supporting 'said thermostatic holding member o r enabling the. same to yield and release the plunger when said plungereis moved to the circuit? 130 for engagement therewith, a movable plun-- .ger for forcing said spring contact into engagement with the first contact, a locking shoulder on said plunger, a thermostatic holding member engaging said locking shoulder, and means yieldingly supporting said thermostatic holding member.

7. In a switch ofthe character described,

a spring pressed contact, a plunger for operatingsaid contact, a locking shoulder on --said plunger, and a thermostatic holding member engaging said locking shoulder movable under heat conditions laterally out of engagement with saidA locking shoulder and yieldable longitudinallyin the direction of retractive movement of the plunger to permit manual retraction of said plunger.

8. In a switch of the character set forth, a switch operating plunger, a thermostatic member for holding said plunger in one position, means for yieldingly supporting said thermostatic member to permit the same to yield as the plunger is moved into a different position, and means for shifting the thermostatic member out of holding engagement with the plunger as said plunger is moved to said last position.

9. In a switch of the character set forth, a switch operating plunger, a thermostatic member for holding said plunger in one position, means yieldingly supporting said thermostatic member to permit said member to yield as the plunger is shifted to a different position and a relatively stationary abutment engaged by the thermostatic memberv during the yielding movement thereof ar ranged to force said member outv of holding engagement with the plunger. f

10. In a switch of the character setforth,

. a switch operating plunger, -a thermostatic memberpivotally supported at one end and engaging the plunger-at its opposite end to hold ysaid plunger in one position, a spring yieldingly holding said thermostatic member in such holding position, and means for disengaging the 4thermostatic member from 'holding engagement' with the plunger as the plunger is moved to al different position.

11. In a switchof the character set forth,

a. switch operating plunger provided with a locking shoulder on the side thereof. a

`thermostatic member. disposed alongside said plunger-and having a locking shoulder engaging the locking shoulder on the plunger, electrical means for shifting said thermostatic member out of holding engagement `with the plunger and manually operable' said locking shoulder and movable under l heat conditions laterally out of engagement" with said locking shoulder, means for heating said thermostatic member, said member being mounted to yield in the direction of retractive movement of the switch operating member and means operable in said retractive movement of the switch operating member to shift the thermostatic member laterally out of holding engagement with the locking shoulder.

13. In combination a switch operating plunger provided with a locking shoulder, a thermostatic holding member pivotally supported at one end and engaging said locking shoulder at'its opposite end, and a spring acting on said pivoted thermostatic member to cause the same to hold the plunger yieldingly in a predetermined position.

14. In combination, a iswitch operating plunger provided with a locking shoulder, a thermostatic holding member pivotally supported at one 'end and engaging said locking shoulder at its opposite end, a spring acting on said pivoted thermostatic member to cause the same to hold the plunger yieldingly in a predetermined position and means for shifting the thermostatic member out of holding engagement with the locking shoulder when the plunger is shifted to a different position.

15. In combination, a switch operating plunger rovided with a locking shoulder, a guide or said plunger and a yieldingly supported thermostatic .member engaging the locking shoulder on the plungei' and adapted to be carried into engagement with the plunger guide in the longitudinal shifting movement of the plunger.

16. In combination, a switch operating plunger provided with a locking shoulder, a thermostatic member yieldable in the direction of retractive movement of said plunger and provided with a locking shoulder engaging over the locking shoulder on the plunger and having an exposed inclined face and a relatively stationary member disposed in the path of said inclined face in the retractive movement of the plunger.

17. In combination, a switch operating plunger provided with a locking shoulder, a thermostatic member yieldable inthe direction of the reti-active movement of the plunger and provided with a locking shoulder engaging over the locking shoulder on the plunger and a `relatively stationary meniber having an inclined wedging face engaged by the thermostatic member in the retractive movement of the plunger.

18. In combination, a movable switch operating dmember, a thermostatic holding member for said switch operating member, electric heating means on saidthermostatic l member, a contact on said thermostatic member for the electric heating means and a circuit controlling device engageable with A said contact.

holding member for said operating member entirely out of circuit during the normal operation o the system.

21. In combination with an ignition circuit including switch contacts, operating meansfor holding the circuit closed through said contacts, an electrically operated thermostatic holding member for the operating member arranged on open circuit condition during the normal operation of the system and a thermostatic circuit closer for closing the circuit through the electrical holding member under abnormal conditions.

22. In combination with a switch operating member, a thermostatic member for holding said switch operating member in a predetermined position, means for shifting said ythermostatic member out of holding engagement with the switch operating member and thermal conducting means for carying oi heat from the thermostatic mem- 23. In combination with a movable switch' operating member, member for said switch operating member, a

a thermostatic holding metallic support of good thermal conductivity and a thermostatic conductor onthe thermostaticmember for engagement with .the metallic support.

24. The combination with a movable switch operating member, a thermostatic holding member for said movable switch operating member yieldable inthe direction of retractive movement of the switch operating member and a stop lting. the movement of the-.yieldable thermostatic member in the opposite direction-. i

25. In a switch of the character described,

' switchrcontacts, an operating plunger there- -,termin al for mounted on the insulating base, a thermo-- for, a thermostatic holding member for said plunger disposed at one side of the plunger and a thermostatic circuit controller for said holding member disposed at the opposite side of the plunger.

26. In combination, a casing, switch contacts in the bottom of said casing, a switch operating kplunger projecting from the top of the casing, a thermostatic holding member for said plunger disposed at one side of the casing at the side of the plunger and a thermostatic circuit controller for said holding member disposed at the opposite side of the casingat the opposite side of the plunger. 27. In combination, switch contacts, a thermostatic circuit controller electrically connected with one of said switch contacts, a thermostatic holding member provided with a contact engaged by the thermostatic circuit controller and a switch operating memberengaged bythe thermostatic holding member.

28. In a switch of the character described, switch contacts, a terminal for one of said contacts, a thermostatic lciicuit controller electrically connected with the other switch contact, a terminal for said circuit controller, a switch operating member, a thermostatic holding member for the switch operating member provided with a contact for engagement by the circuit closer and a terminal for the thermostatic holding member.

29. In a switch of the character described, a metallic support, an insulating terminal base carried by said support, insulated switch contacts mounted on the support, a

one of said switch contacts static circuit controller electrically connected with the other switch contact, a terminal for said circuit controller mounted on th'e insulatingybase, a movable switch operating member, a thermostatic holding member for the switch operating-member electrically connected with the metallic support and provided with a contact for engagement by the circuit controller and a circuit terminal on the metallic support.

l30. In a switch of the character described,

a metallic casing having anopening in one side and a tongue pro]ecting,in the opening,

an insulating base closing said opening and resting on the tongue aforesaid and a tubular circuit terminal securing the insulating base to the tongue.

. 31. In combination with a switch operating member, a quickly responsive holding thermostat for the same provided withr a heating coil of relatively fine wire and a thermostatic circuit closer for the heating circuit of the holding thermostat provided with a lheating coil wire.

of relatively heavier 32. In combination Witha, switchoperat- `ing member, a holding thermostat for the same lprovided with a U-shaped base and a l pivotal support for said thermostat extend- 5 ing through the side arms of said U-shaped ase.

33. In combination with a switch operating plunger, a holding thermostat for the same and a locking shoulder on the plunger engaged bythe thermostat and providedv 10 with an inclined surface for Wedging engagement With the thermostat.

JOHN F. CAVANAGH. 

